wright



(No Model.) 2 Sheets-Sheet 1.

J. J. WRIGHT.

SAFETY DEVICE FOR ELECTRIC LAMPS. No. 258,521. Patented May 23, 1882.

* UNITED STATES PATENT OFFICE.

JOHN JOSEPH \VRIGHT, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO GEORGE S. GARRETT, OF SAME PLACE.

SAFETY DEVICE FOR ELECTRIC LAMPS.

SPECIFICATION forming part of Letters Patent No. 258,521, dated May 23, 1882,

Application filed July 9, 1881. (No model.)

To all whom it may concern Be it known that I, JOHN JOSEPH WRIGHT, of the city and county of Philadelphia, State of Pennsylvania, have invented certain new and useful improvements in an automatic safety device for preventing a break in a circuit when a number of electric lamps are employed in series; and I do hereby give such a description of the same as will enable those skilled in the art to make and practice my invention.

It is well known to those skilled in electrical science that when a number of electric lamps are connected in series in the same circuit 1 an interruption of the current in any one of the lamps or devices used will extinguish all the others in the same circuit. The object of my invention is to anticipate and prevent such a break or interruption of the continuity of the circuit. I accomplish this substantially as follows: When through anycause the mechanism of any lamp fails to operate to approach or bring together the carbon points or electrodes of that lamp the length of are between the 2 5 electrodes gradually increases by reason of their consumption. hen the length of arc has reached a certain limit, which I can vary at pleasure, I cause the electrodes to be forcibly driven into contactby theaction of a spring 0 or its mechanical equivalent. The mechanism by which the carbons are thus driven together is thrown into action by a movement of the armature of an electro-magnet placed ina derived circuit around the electrodes. By this means, as is well known in the art, the increase in the resistance of the arc causes a proportionately greater portion of the current to traverse the coils of the electro-magnet, controlling the mechanism for driving the carbons together.

Figure 1 shows a sectional view of the means employed to bring, the carbon points or electrodes into contact. Fig. 2 shows an enlargement of the part comprising the groove and 5 lever.

Fig. 1 shows a sectional view of the lowercarbon holder of an electric lamp furnished with my automatic safety device for preventing a break in the circuit. This device con- 5o sists, as shown, of a contrivance by which the lower electrode, E, is forced by the action of the spring S into electrical contact with the upper electrode, E. The lower clamp or carbon-holder, B, slides easily in a vertical direction withinthe outer support or column, M. The holder B has near its lower end a groove, G, in its outer circumference. When the carbon-holder is forced down into its normal position it compresses the spiral spring S and brings its groove G into position to be engaged by the bent lever T. The length of the lever T is so proportioned that when engaged in the groove G its upper end is held by the hook K of the armature-lever L, pivoted at Y. An armature, A, connected, as shown, with the lever L, is placed over the poles and within the influence of an clectro-magnet, (J 0, whose coils form the whole or a part of a derived circuit of high resistance around the electrodes.

Fig. 3 is a sectional view of the apparatus on the line D.

. Fig. 4 is a diagram of the manner in which the connections with a lamp may be made; E E, upper and lower electrodes; F, shunt or feedingmechanism of the lamp; W, main wire of circuit; Q, wire of derived circuit or shunt; C, magnet of safety device herein described.

Fig. 5 is a diagram showing the connections in the event of the entire wire of the derived circuit being utilized to operate my safety device, as described; E E, upper and lower electrodes; W, main wire of circuit; Q, wire of derived circuit or shunt; (J, magnet of safety device herein described.

The method of operation is substantially as follows: lffrom any cause the resistance of the are between the electrodes E E is increased beyond an amount previously determined on, the proportion of current traversing the coils G of theshunt-magnet 0, being thereby in- 0 creased, causes a movement of the armature A and its lever L,whereby the hook K is raised sufficiently high to release the lever T. At this moment the spring S, acting on the short arm of theleverT, disengages it from the groove 5 and forces the elect-rodeE into close and good electrical contact with the upper electrode, E.

To bring the electrodeE into its normal working position, it is only necessary to force it downward until the groove Gis in position to I00 be again engaged by the bentlever T, as hereinbefore described. Since the attraction of the electro-magnet O on its armatureA is dependent on the distance apart of the electrodes E E during action, it is evident that the moment the releasing mechanism is thrown into action may be determined by the tension of -the spring S.

The lever T is pivoted at O, as shown, in order that the strong upward pressure of the spring S may be diminished on the hook K in the ratio of the leverage of the arms of the lever T, allowing a comparatively feeble current in the coils of the magnet G to operate with promptness and certainty in releasing the mechanism connected therewith.

I do not restrict myself to the exact arrangementofparts described in connection with Figs. 1, 2, 3, 4t, 5, since the shunt-magnet may be utilized to throw into action any mechanical equivalent by which a spring or the force of gravity may be employed to bringthe electrodes into contact.

I claim as my invention and desire to secure by Letters Patent- 1. In combination with an electric-lamp carbon-holder, an automatic safety device consisting substantially of an electro-magnet in a derived circuit around the electrodes, an armature therefor, acatch or detentin operative combination with said armature, as described, and a spring held compressed by said detent until released by a movement of said armature on an increase in the power of said derived-circuit magnet.

2. In an electric lamp, the combination of a carbon-holder, a spring to elevate the same, a

detent to engage the carbon-holder when the sameis depressed againsttheface of the spring, a lever provided with an armature, and a device to hold the detent in engagement with the carbon-holder and a magnet in a shuntcircuit,whereby the carbon-holder may be held in position while the lamp is burning, but will be released and forced against the ODPOSlllg carbon on an abnormal increase of current in the shunt-circuit, as described.

3. In asafety circuit-preserver, a setting and releasing device consisting of the part B and its groove G, or their equivalents, and of the lever T and lever L, with projection K, or their mechanical equivalents, substantially as described.

4. In an electric lamp,the combination,with a shunt or derived circuit magnet around the are of said lamp, of its ari'nature, a lever, L, hook or catch K, and detent-lever T, a carbonholder, B, and grooved sleeves G, substantially as specified.

5. In combination with a carbon-holder of an electric lamp, a derived-circuit magnet around the arc and armature thereof, and mechanism, constructed substantially as set forth, whereby movement is imparted to said carbon-holder by a spring released by said derived-circuit magnet on an abnormal increase in its power.

In testimony whereof I have signed my name to this specification in presence of two subscribing witnesses.

JOHN JOSEPH WRIGHT.

Witnesses:

Gno. S. GARRETT, I. E. ARNOLD. 

